The present invention relates to a tumble forward vehicle seat and in particular to tumble forward seat having a raised pivot point at the front of the seat about which the seat pivots as it is being tumbled forward.
Various embodiments of so-called "tumble forward" seats have been developed. Such seats are used as second or third row seats in a multi-purpose passenger vehicle or van and are formed so that they can be stored in a folded condition to make available a larger space in the vehicle for cargo. In a typical case, the seat frame is pivotally attached to the vehicle floor at the seat front end and is releasably attached to the vehicle floor at the rear end. To fold the seat, the seat back is first rotated forward to a horizontal position, resting upon the seat cushion. The seat frame is then released from the floor at the rear of the seat frame, allowing the frame to be rotated to an up-tilted position by raising the rear end of the frame upward and forward. Typically, the seats are also releasably mounted to the vehicle floor at the front end by latching the seat to a transversely extending mounting pin in the vehicle floor. The mounting pin serves as the pivot pin about which the frame rotates as the seat is tumbled forward.
It is desired that such seats include a biasing means for raising the seat without assistance once the seat is released at its rear end. In order for the seat to pivot about the front mounting pin, it is necessary to provide some form of linkage bearing against the vehicle floor to provide the force necessary to rotate the seat. Once folded, the seat must be held in the folded position throughout the operating motions of the vehicle. The required force to hold the seat in the folded position depends upon the extent of seat rotation to the folded position. The extent of rotation in turn depends upon the vehicle geometry, the seat design, the distance between the folding seat and the seat in front of it, etc. If the seat can be rotated far enough to raise the seat center of gravity over and forward of the pivot axis, less force is needed to retain the seat in the folded position than if the center of gravity is raised but remains behind the pivot axis. To increase the amount of seat rotation, it may be necessary to decrease the size of the seat cushion foam at the front of the seat cushion. This allows for more seat rotation before the cushion contacts the vehicle floor. The biasing force used to fold the seat and retain it in position must not be so great, however, as to prevent a vehicle operator from easily returning the seat from the folded positioned to the use position in opposition to the biasing force.
The seat assembly of the present invention overcomes the above disadvantages in prior art tumble forward seats by providing a front mounting bracket which is rigidly and releasably attached to the vehicle floor through a pair of longitudinally spaced mounting pins in the vehicle floor at the front of the seat. The seat frame is pivotally attached to the mounting bracket. When the seat is rotated to the folded, stowed position, the seat rotates about a pivot axis which is spaced above and separate from the mounting pins in the vehicle floor.
It is an advantage of the seat of the present invention that the seat pivot location can be optimized to provide a maximum rotation of the seat center of gravity and which minimizes the amount of foam cut away at the front of the seat cushion to achieve the desired seat rotation.
It is another advantage of the seat of the present invention that a relatively small opening can be provided in the vehicle floor for attaching the seat to the mounting pins since the seat does not rotate within the floor opening about one of the mounting pins.
It is a further advantage that since to the seat pivot is integral with the seat mechanism, the pivot can be lubricated and a longer life provided.
It is yet another advantage that with dual front mounting pins and a single rear mounting pin, it is impossible to install the seat in a rearward facing direction.
It is still a further advantage of the seat of the present invention that the front latch for installing the seat in a vehicle is non-releasable when the seat is in its use position.
Further objects, features and advantages of the invention will become apparent from a consideration of the following description and the appended claims when taken in connection with the accompanying drawings.